Aluminium T6

Solution heat treatment is done by heating the alloy temperature to about 530°c and holding it there for approximately an hour.

The purpose of this is to dissolve all the alloying elements in a solid solution in the aluminium, before then quenching the alloy in water. The purpose of quenching is to strengthen the alloy and stop it precipitating on cooling – once quenched, the aluminium will be in a T4 state.

If we heat the material again to 200°c for four hours, the alloying elements begin to form ordered arrays of atoms in the aluminium. These arrays are called GP zones, and they strengthen the aluminium considerably. This heat treatment is called aging, which results in material with a T6 temper.